I've flowed heads a good bit with intakes and carburetors.
Here's an example of a ported OEM SB head w/Victor 340
and Holley 750.

................HEAD.............W/IN&CARB

.100"______63.8__________63.8
.200"_____134.7_________134.5
.300"_____193.8_________190.7
.400"_____244.2_________233.3
.500"_____257.4_________240.3
.550"_____258.4_________243.4
.600"_____260.1_________245.5

Intake had a good port match and minor work in the plenum.